You need to get an overflow box. like this
http://www.marinedepot.com/CPR_CS90...13-vi.html

are you going to get a new skimmer and put in your sump? for some good sump ideas go to http://www.melevsreef.com/allmysumps.html then on the left side of that page it tells you how to make a sump and what not. a refugium is basically an area to grow Cheato and other macro algae and keep live rock to act as more filtration and grow copeds and other little reef critters that fish will feed on. that site has a lot of information on it. i have a 55g in bussey that already has chambers made for a sump but it wont fit under your stand

when you add the sand in the refugium does that need to cycle before it can go in the fishtank? or do you just hook up and go.

it will cycle. i didn't use sand in my last tank. you will hear mixed thoughts on sand in your fuge